in 1998. Use They are used extensively in Switzerland and in Spain, in the latter country to transport standard gauge vehicles on broad gauge lines. They are also in use on the Harz Narrow Gauge Railways to transport limestone from the Unterberg quarry to Nordhausen, where they are transferred to the DB system at a pit between the station and Hesseröderstraße. Trains are diesel-hauled and typically consist of 12 Fccpps ballast hopper wagons from Voestalpine Railpro; the Rollböcke are painted bright pink. Until the 1990s the Rollbock sidings at Wernigerode were used every day to transport goods to and from the various metallurgical factories attached to the Harz Narrow Gauge Railways in the immediate area. Similarly it was used extensively on the Saxon narrow gauge system west of Dresden to transport china clay to Meissen. Using rollbock technology requires that the narrower gauge network must be built to a structure gauge large enough to accommodate the loading gauge of standard gauge wagons, and that negates one of the cost advantages of narrower gauge construction. The system was tested for the narrow gauge railways in Saxony around 1900 but it found only rare application - tracks requiring higher transport capacity were rebuilt to instead. However it is also possible to use the wagons of the narrow gauge loading gauge type built with standard gauge axles which allows them to run at full speed on standard gauge tracks, piggybacking them on the short section in the mountains by Rollbock bogies. This application requires that the receiver of the freight is able to unload those wagons, so they have found only limited use. Gallery See also Break of gauge Dual gauge Bogie exchange Transporter wagon Narrow gauge railways in Saxony References Bibliography Jackson, Alan A. (2006). The Railway Dictionary, 4th ed., Sutton Publishing, Stroud. . External links Video of Rollböcke in use between Unterberg and Nordhausen (detail of unloading at minute 20) Rail infrastructure Freight rolling stock